I think there needs to be a consideration of the financial position of both Sony's Game division and Sony on the whole ...
The decline of sales of hardware and software of both the PSP and PS2 have really cut into Sony's game division's bottom line because these systems are not sold at (much of) a loss and the licencing fees alone off of the software where boosting the profit margin of the division. Its difficult (if not impossible) for Sony to recover these lost revenues from the PS3 (in particular with a price cut) because the hardware does have a noticeable loss, there is a massive ammount of money spent on marketing (and more would be needed), the total volume of software isn't as great, and the per unit profit off of software is limited due to higher development costs. When you add to this the added costs of launching the PSP go it becomes clear that it would be a challenge for the game division to cut the price of the PS3.
On top of all of that, Sony on the whole is bleeding money and needs most of its divisions to turn a profit if they can or to reduce their losses if they can't turn a profit. It would be a difficult for SCE to convince the board of directors of Sony that it was a good idea to take a $1 Billion loss on the PS3 at this point in time.
I'm not saying it can't or won't happen, just I don't think most people realize how difficult it would be for SCE to justify a price cut.